Vent valve



FIG. 1 is a top plan view of the valve;

FIG. 2 is an elevated front view thereof;

FIG. 3 is an inverted rear view thereof;

FIG. 4 is an on-end left side view, the right side being a mirror imagethereof;

FIG. 5 is a bottom view thereof; and,

FIG. 6 is a perspective view of said bottom.

I claim the ornamental design for a vent valve, as shown and described.